Conventional power save mechanisms in a wireless local area network (WLAN) operating under IEEE 802.11 may utilize a periodic beacon transmitted by the access point (AP) to inform an associated station (STA) in power save mode that data is pending delivery. Generally, the traffic indication map (TIM) information element (IE) in the beacons includes information regarding unicast traffic, allowing a STA to determine whether to poll the AP to initiate transfer of data that has been buffered. Delivery of group traffic, on the other hand, is not initiated by the stations. Rather, a subset of the beacons, known as delivery TIM (DTIM) beacons, are transmitted at a periodicity advertised by the AP and may be used to indicate that group traffic has been buffered and will be transmitted following the DTIM beacon.
Accordingly, a STA typically will be configured to awaken in order to receive the DTIM beacon and may remain awake to receive the data when the DTIM beacon indicates there is buffered group traffic, as otherwise a STA that remains in power save mode would miss any transmitted group traffic. Consequently, the STA interrupts the power save mode and awakens at every DTIM interval to receive the beacon, whether or not data is pending delivery. When no data is pending, this periodic awakening represents unnecessary power expenditure.
As will be appreciated, there is a need for systems and methods to coordinate delivery of buffered data in a manner that conserves power at a STA. In turn, there is a need to communicate DTIM information to a STA in a manner that reduces interruptions when operating in a power save mode. This disclosure satisfies these and other needs.